[PATCH v10 0/6] RISC-V: Detect and report speed of unaligned vector accesses

[Charlie Jenkins]

Adds support for detecting and reporting the speed of unaligned vector
accesses on RISC-V CPUs. Adds vec_misaligned_speed key to the hwprobe
adds Zicclsm to cpufeature and fixes the check for scalar unaligned
emulated all CPUs. The vec_misaligned_speed key keeps the same format
as the scalar unaligned access speed key.

This set does not emulate unaligned vector accesses on CPUs that do not
support them. Only reports if userspace can run them and speed of
unaligned vector accesses if supported.

Signed-off-by: Charlie Jenkins <charlie at rivosinc.com>
Signed-off-by: Jesse Taube <jesse at rivosinc.com>
---
Changes in V6:
 Added ("RISC-V: Scalar unaligned access emulated on hotplug CPUs")

Changes in V8:
 Dropped Zicclsm
 s/RISCV_HWPROBE_VECTOR_MISALIGNED/RISCV_HWPROBE_MISALIGNED_VECTOR/g
  to match RISCV_HWPROBE_MISALIGNED_SCALAR_*
 Rebased onto palmer/fixes (32d5f7add080a936e28ab4142bfeea6b06999789)

Changes in V9:
 Missed a RISCV_HWPROBE_VECTOR_MISALIGNED...

Changes in V10:
- I sent on behalf of Jesse
- Remove v0 from clobber args in inline asm and leave comment

---
Jesse Taube (6):
      RISC-V: Check scalar unaligned access on all CPUs
      RISC-V: Scalar unaligned access emulated on hotplug CPUs
      RISC-V: Replace RISCV_MISALIGNED with RISCV_SCALAR_MISALIGNED
      RISC-V: Detect unaligned vector accesses supported
      RISC-V: Report vector unaligned access speed hwprobe
      RISC-V: hwprobe: Document unaligned vector perf key

 Documentation/arch/riscv/hwprobe.rst       |  16 +++
 arch/riscv/Kconfig                         |  58 ++++++++++-
 arch/riscv/include/asm/cpufeature.h        |  10 +-
 arch/riscv/include/asm/entry-common.h      |  11 --
 arch/riscv/include/asm/hwprobe.h           |   2 +-
 arch/riscv/include/asm/vector.h            |   2 +
 arch/riscv/include/uapi/asm/hwprobe.h      |   5 +
 arch/riscv/kernel/Makefile                 |   3 +-
 arch/riscv/kernel/copy-unaligned.h         |   5 +
 arch/riscv/kernel/fpu.S                    |   4 +-
 arch/riscv/kernel/sys_hwprobe.c            |  41 ++++++++
 arch/riscv/kernel/traps_misaligned.c       | 139 +++++++++++++++++++++++--
 arch/riscv/kernel/unaligned_access_speed.c | 156 +++++++++++++++++++++++++++--
 arch/riscv/kernel/vec-copy-unaligned.S     |  58 +++++++++++
 arch/riscv/kernel/vector.c                 |   2 +-
 15 files changed, 474 insertions(+), 38 deletions(-)
---
base-commit: 98f7e32f20d28ec452afb208f9cffc08448a2652
change-id: 20240920-jesse_unaligned_vector-7083fd28659c
-- 
- Charlie